Sleep Shortage Doubly Dangerous

Many people think they'll get by fine without a full night's sleep. Find out why missing just a little can accumulate a sleep debt that is dangerous.

In the U.S.and other Western countries, the concept of "burning the candle at both ends" has become a part of many people's lives. Many believe they can squeeze more out of their day by going to bed "a little later" or waking up "just a little earlier."

The amount of sleep each person needs can vary, but most adults need between 7 and 8 hours per night. You may sleep more lightly and for shorter periods as you age, but you still need about the same amount you did when you were younger. When you get too little sleep, you contribute to "sleep debt."

Sleep debt is like being overdrawn at a bank. If you miss sleep, it needs to be paid back - with interest. The amount of sleep you need increases if you've missed any, and in time your body will demand that the debt be repaid.

You may think that you can adapt to getting less sleep or get used to it. But your judgment, reaction time and other cognitive functions are impaired without that rest.

Impaired performanceTests of sleep-deprived people show that they perform tasks as badly or worse than intoxicated people. Stimulants like caffeine don't cancel out the effects of severe sleep loss. Sleep deprivation often leads to problems with:

Attention

Vigilance

Memory

Decision making

Reaction/response times

Judgment

In one study 48 healthy people were split into groups that would spend 4, 6 or 8 hours in bed per night for 14 days. The performance of those who slept 6 hours or less was similar to levels observed in people with two nights of total sleep deprivation. And people in this group were largely unaware of their performance deficits.

Driver fatigue is cited in about 100,000 motor vehicle accidents and 1,500 deaths each year. If you have trouble focusing, can't stop yawning or can't remember driving the last few miles, you're too drowsy for safe driving.

The physical cost of sleep deprivationGrowing evidence suggests there is a connection between sleep and health. The most benefits occur during deep or "rapid eye movement" (REM) sleep, which usually occurs between the sixth and eighth hours of sleep.

Sleep seems to help your nervous system. It may give neurons (nerve cells) a chance to shut down and repair. One theory is if neurons are overworked or get polluted with byproducts from other cells, they may not work right.

During deep sleep, growth hormones are released in kids and young adults. Deep sleep also gives your body's cells a chance to raise the production and lower the breakdown of proteins. Proteins are the building blocks of cell growth and repair.

During REM, the brain puts new information in long-term memory. REM sleep lets the brain replenish the mechanisms for memory, learning, performance and problem solving. So, sleeping less than 6 hours may stop you from retaining information.

Sleep deprivation may affect the immune system. Some recent evidence suggests that sleep debt can make you more vulnerable to:

Common viral illnesses

Diabetes

Obesity

Heart disease

Depression

More research is needed to see how lack of sleep affects these illnesses.

The cost to society of people losing sleep or leaving sleep disorders untreated is great. People who have sleep loss, sleep disorders or both are less productive, seek more health care and are at risk for more accidents.

By making a commitment to better sleep habits, you may be able to avoid many health risks. Getting to bed on time and getting needed rest is really more than a habit; it may be a key to healthier life.